56 
The A)iicricaii Geologist. 
Januarj-, 189{>- 
mining, and thus another thousand tons per acre of this bed 
is wasted, though in the Fairmont and Cumberland (Georges 
Creek) regions it is mined and sold with the rest of the coal. 
The twelve to fifteen inches of good fuel in this member 
could always be recovered by crushing and washing. 
The structure here described can be best illustrated by 
giving an actual section of the coal at its type locality. In 
the Ormsby mine at Twenty-first street, Pittsburg, where 
mining operations have been carried on for more than 60 
years, Mr. J. Sutton Wall took the following measurements 
(K 4, Second Geological Survey, Pennsylvania, page 177): 
Inches. 
Coal 
Clay. 
Clay 
6 ^ 
Parting oj. 
Coal 2 
Clay 9 ■ 
Coal 8 
'Roof " ■ ■ \ Parting oi 
Coal Q 
Clay o\. 
Coal 5 
Parting oi 
Coal 2 
Parting oi 
(^ Coal 2 
'Over"-clay 
'Breast" coal 33 " 
Parting o^ 
'Bearing-in" coal 4 
Parting q\ 
'Brick" coal 10 
Parting o^ 
'Bottom" coal 14 
Total thickness 
)-56" 
J- 6ii 
10 '61" 
Substantially this structure may be seen at every mine 
between Pittsburg and Brownsville, and on beyond for many 
miles (see Reports K and K 4, Second Geological Survey,. 
Pa). 
East of the Monongahela, on the Youghiougheny river, 
the same structure is well illustrated by two sections which 
Mr. W. S. Gresley, F. G. S. A., measured for me with great 
care at the W. L. Scott estate mines, of which Mr. Gresley 
is superintendent at Scott Haven, Pennsylvania. The first 
one of these is near Scott Haven, and reads as follows: 
